change from http to https from a specific form

[Brian Marshman]

What is the right way to write this script;
<FORM ACTION=$ENV{'SCRIPT_NAME'} METHOD=POST>
<INPUT TYPE=HIDDEN NAME=action VALUE=procreg>
<INPUT TYPE=HIDDEN NAME=IP VALUE=$ip>

to read something like this <FORM ACTION="https://theURL"> what would be the rest? and when the form is filled out returns to http